<?php
        define('DB_HOST','localhost');
        define('DB_USER','hecheng');
        define('DB_PASS','111');
        define('DB_NAME','review_app');

        $conn = new mysqli(DB_HOST,DB_USER,DB_PASS,DB_NAME);
        if ($conn->connect_error){
            die("连接失败".$conn->connect_error);
        }
        echo "连接成功！";